1. Field of the Invention
This invention relates to restraint devices and in particular to the restraint of pictures and other wall hangings which might be inadvertently knocked loose from their hangers.
2. Background Art
Heretofore, most devices for mounting pictures were designed to satisfy two needs. These needs are, one, to allow the aesthetic centering of the wall hanging, and, two, to provide easy installation and removal of the wall hanging. In regions of frequent seismic activity it is necessary to satisfy another need. That need is to secure the wall hanging against being jostled into falling. By falling, it might be damaged or might strike and injure a person. Furthermore, in regions of earthquake activity, local governmental agencies recommend secondary securement to prevent injury or damage during seismic activity.
Search for prior art revealed a limited number of devices which attempt to satisfy all three needs. Each of these devices has disadvantages and none has the advantage of providing a redundant securement system. The first identified prior art is U.S. Pat. No. 1,858,875 (Blumenthal) issued May 17, 1932. Blumenthal's device will satisfy the securement criterion cheaply and simply, but only if the hanger nail is sunk into wood. However normally hanger nails are sunk into common drywall. In such circumstances the device fails the securement objective in that the nail can slip out during an earthquake. In any case the device fails the aesthetic criterion. Also it must be completely pulled from the wall in order to remove the picture.
U.S. Pat. No. 3,612,469 (Dennis) issued Oct. 12, 1971 is designed to prevent theft and is positively secure against earthquakes, but it is heavy, complex, expensive, time consuming; and the aesthetic hanging of the object is a major task.
Both U.S. Pat. No. 4,074,888 (Garner) issued Feb. 21, 1978 and U.S. Pat. No. 4,458,872 (Couch) issued Jul. 10, 1984 are complex and require meticulous positioning of the hanging apparatus on the picture frame. Failure to exactly center the device would cause the picture to tilt and therefore not hang aesthetically. In such cases reinstallation of the device would be required. This would be frustrating and time consuming.
U.S. Pat. No. 4,821,992 (Johnson) issued Apr. 18, 1989 fails its securement objective because it is secured to the wall with a simple hanger nail. For aesthetic reasons most hanger nails will be mounted into drywall. Drywall offers little resistance to a nail being jostled or pulled out of the wall. Consequently it is possible that this hanger could be jarred free from the wall during an earthquake.